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KMT

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Slide 1:

1

What is KMT? :

2 What is KMT? Based on the research of Robert Boyle (1627 – 1691)
A theory that envisions molecules in motion
Best describes properties and behaviors of gases
* Imagines particles of a gas like billiard balls, moving and crashing into each and the walls of a container in a three-dimensional space.

Visualizing Molecular Motion (KMT) :

3 Visualizing Molecular Motion (KMT)

Kinetic Molecular Theory* :

4 Kinetic Molecular Theory* All matter consists of extremely tiny particles (atoms and molecules) that are in constant motion
The different states of matter are due to the different spacing and energy of the particles
An additional aspect of the kinetic-molecular theory is the dependence on temperature - Increasing temperature corresponds to faster and faster motions of atoms and molecules and increased spacing.
The basic principles of KMT are theoretical and begin to break down under certain circumstances KMT is better at describing matter in higher energy states (gases, for example)

Slide 5:

Chumbler - Properties of Matter 5 The Three States of Matter
Based upon particle arrangement
Based upon energy of particles
Based upon distance between particles
Matter - anything that occupies space and has mass

Classifying Matter :

6 Classifying Matter States of Matter
Solid - has a rigid shape and a fixed volume that changes very little with temperature and pressure
Liquid - like solids have a fixed volume but no definite shape (take on the shape of the container)
Gas - no fixed volume - volume determined by the size of the container - the volume of a gas varies greatly with temperature and pressure

Solid :

7 Solid definite volume
definite shape
atoms are packed together in fixed positions
strong attractive forces between atoms
only vibrate in place

Slide 13:

States of Matter Solid Liquid Gas Definite Volume? YES YES NO Definite Shape? YES NO NO Temp. increase Small Expans. Small Expans. Large Expans. Com-pressible? NO NO YES

Changes of State :

14 Changes of State

Slide 15:

Solid Liquid Gas

Matter :

Matter All matter is composed of 100 or so __ELEMENTS_____
A substance that cannot be separated into simpler substances by a chemical change; simplest type of pure substance.
The building block of matter is the __ATOM_____
The smallest particle of an element that retains the chemical identity of the element.
Atoms can combine to form COMPOUNDS

Elements and Compounds = Pure Substances :

Elements and Compounds = Pure Substances Element = Matter that is composed of only one type of atom
Currently 116 elements are known to exist
Only about 90 of these are found in nature - the remainder were synthesized by scientist
The elements are listed in the Periodic Table Compound= Compounds are composed of molecules with more than 1 type of atom
Molecules are defined combinations of atoms that are chemically attached (“chemically bonded”):

Pure Substances :

Pure Substances Elements- simplest kind of matter
Cannot be broken down into simpler
All one kind of atom.
Compounds are substances that can be broken down by chemical methods
When they are broken down, the pieces have completely different properties than the compound.
Made of molecules- two or more atoms stuck together

Mixtures Made up of two substances. Variable composition.Mixtures can be; :

Mixtures Made up of two substances. Variable composition.Mixtures can be; Homogeneous= same composition throughout.
Every part keeps its properties
Kool-aid, air, salt water Heterogeneous= mixture is not the same from place to place.
Chocolate chip cookie, gravel, soil.

Solutions :

Solutions Homogeneous mixture
Mixed molecule by molecule
Can occur between any state of matter.
Solid in liquid- Kool-aid
Liquid in liquid- antifreeze
Gas in gas- air
Solid in solid - brass
Liquid in gas- water vapor

Solutions :

21 Solutions solvent
what does the dissolving
larger volume solute
what is being dissolved
smaller volume

Examples of Mixtures :

22 Examples of Mixtures

Classification of Matter :

Classification of Matter Matter can be classified as either Pure or Mixture:
Pure
Element: composed of only one type of atom
Composed of either individual atoms or molecules (e.g. O2)
Compound: composed of more than one type of atom
Consists of molecules
Mixture
Homogeneous: uniform throughout, appears to be one thing
pure substances
solutions (single phase homogeneous mixtures)
Suspensions (multi-phase homogeneous mixtures)
Heterogeneous: non-uniform, contains regions with different properties than other regions

Compound or Mixture :

25 Compound or Mixture Compound Mixture One kind of piece-
Molecules More than one kind -
Molecule or atoms Making is a
chemical change Making is a
physical change Only one kind Variable composition

Which is it? :

26 Which is it?

Separation Techniques :

27 Separation Techniques Filtration- solid part is trapped by filter paper and the liquid part runs through the paper
Vaporization- where the liquid portion is evaporated off to leave solid

Separation Techniques :

28 Separation Techniques Decanting- when liquid is poured off after solid has settled to bottom
Centrifuge- machine that spins a sample very quickly so that components with different densities will separate

Separation Techniques :

29 Separation Techniques Paper Chromatography- used to separate mixtures because different parts move quicker on paper than other

Properties of Matter :

Properties of Matter Physical
Characteristics can be observed without altering the identity of the substance
Volume
Mass
Maleability, ductility, conductivity etc… Chemical
Characteristics cannot be observed without altering the identity of the substance
Flammability
Tendency to corrode
Reactivity
Etc…

Physical Properties (continued) :

31 Physical Properties (continued) Extensive and Intensive Properties
Extensive properties depend on the amount of a substance present. Examples are mass and volume.
Intensive properties are those that do not depend on the amount of substance (e.g., melting point, boiling point, and density)
Ice melts at 0oC no matter whether you have an ice cube or an iceberg

Changes Matter Can Undergo: :

Physical Changes & Chemical Changes :

Physical Changes & Chemical Changes Physical Changes : A change that changes appearances, without changing the composition.
Examples?
Chemical changes - a change where a new form of matter is formed.
Also called chemical reaction.
Examples?
Not phase changes
Ice is still water.

Physical and Chemical Change :

35 Physical and Chemical Change Chemical changes (or chemical reactions) involve transformation of one or more substances (reactants) into one or more different substances (products)

Chemical changes often involve a transfer of energy! :

36 Chemical changes often involve a transfer of energy!

Chemical Change :

37 Chemical Change A symbolic representation of chemical changes is called a chemical equation.

Distinguishing Chemical from Physical Change :

Distinguishing Chemical from Physical Change Did the change produce a different substance?
Was there a color change?
Is there a different density?
Is there a melting or boiling point change?
Did something precipitate ( solid formed) out of solution?
Did a gas or smoke form?
Was there (a lot of ) energy released or absorbed